talk/test/mcp_test.go

package test

// Process-boundary tests for the MCP endpoint (Task 06): the complete
// handshake (initialize → notifications/initialized → tools/list →
// tools/call) as raw JSON-RPC HTTP payloads against a real talkd — literal,
// without a client SDK. tools/call must behave exactly like POST /speak: the
// same queue admission including mute and law.

import (
	"fmt"
	"net/http"
	"strings"
	"testing"
	"time"
)

// mcpToolText reads content[0].text from a tools/call result.
func mcpToolText(t *testing.T, m map[string]any) string {
	t.Helper()
	result, ok := m["result"].(map[string]any)
	if !ok {
		t.Fatalf("tools/call without result: %v", m)
	}
	content, ok := result["content"].([]any)
	if !ok || len(content) == 0 {
		t.Fatalf("tools/call without content: %v", result)
	}
	first, ok := content[0].(map[string]any)
	if !ok {
		t.Fatalf("content[0] is not an object: %v", content[0])
	}
	text, _ := first["text"].(string)
	return text
}

// mcpIsError reads isError (missing = false — deliberate semantics).
func mcpIsError(m map[string]any) bool {
	if result, ok := m["result"].(map[string]any); ok {
		if e, ok := result["isError"].(bool); ok {
			return e
		}
	}
	return false
}

// TestMCPHandshake (acceptance criterion): the curl sequence initialize →
// notifications/initialized → tools/list → tools/call sees the speak tool
// and enqueues successfully — the announcement runs through the queue and
// the fake provider.
func TestMCPHandshake(t *testing.T) {
	root := t.TempDir()
	fake := newFakeProvider(t, 0)
	d := startDaemon(t, root, fake.srv.URL, nil)

	// 1. initialize: the requested version is echoed; capabilities name
	//    tools; serverInfo is talkd.
	raw := mcpPost(t, d, `{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"curl-test","version":"0"}}}`)
	if raw.status != http.StatusOK {
		t.Fatalf("initialize: status %d — body: %s", raw.status, raw.body)
	}
	if ct := raw.header.Get("Content-Type"); !strings.HasPrefix(ct, "application/json") {
		t.Errorf("initialize Content-Type = %q, want application/json", ct)
	}
	m := mcpDecode(t, raw)
	if m["jsonrpc"] != "2.0" || fmt.Sprint(m["id"]) != "1" {
		t.Fatalf("initialize envelope = %v (check jsonrpc/id)", m)
	}
	result, ok := m["result"].(map[string]any)
	if !ok {
		t.Fatalf("initialize without result: %v", m)
	}
	if result["protocolVersion"] != "2025-06-18" {
		t.Errorf("protocolVersion = %v, want echo of the requested 2025-06-18", result["protocolVersion"])
	}
	caps, ok := result["capabilities"].(map[string]any)
	if !ok {
		t.Fatalf("capabilities = %v, want object", result["capabilities"])
	}
	if _, ok := caps["tools"]; !ok {
		t.Errorf("capabilities without tools: %v", caps)
	}
	serverInfo, _ := result["serverInfo"].(map[string]any)
	if serverInfo["name"] != "talkd" {
		t.Errorf("serverInfo.name = %v, want talkd", serverInfo["name"])
	}
	if v, _ := serverInfo["version"].(string); v == "" {
		t.Error("serverInfo.version is empty")
	}

	// Another requested version is echoed as well (accepted).
	raw = mcpPost(t, d, `{"jsonrpc":"2.0","id":2,"method":"initialize","params":{"protocolVersion":"2025-03-26"}}`)
	m = mcpDecode(t, raw)
	if m["result"].(map[string]any)["protocolVersion"] != "2025-03-26" {
		t.Errorf("protocolVersion = %v, want echo 2025-03-26", m["result"])
	}

	// 2. notifications/initialized: notification → 202 without body.
	raw = mcpPost(t, d, `{"jsonrpc":"2.0","method":"notifications/initialized"}`)
	if raw.status != http.StatusAccepted {
		t.Fatalf("notifications/initialized: status %d, want 202", raw.status)
	}
	if raw.body != "" {
		t.Errorf("notifications/initialized body = %q, want empty", raw.body)
	}

	// 3. tools/list: exactly the speak tool with the briefed schema.
	raw = mcpPost(t, d, `{"jsonrpc":"2.0","id":3,"method":"tools/list"}`)
	m = mcpDecode(t, raw)
	result = m["result"].(map[string]any)
	tools, ok := result["tools"].([]any)
	if !ok || len(tools) != 1 {
		t.Fatalf("tools = %v, want exactly one tool", result["tools"])
	}
	tool := tools[0].(map[string]any)
	if tool["name"] != "speak" {
		t.Errorf("tool.name = %v, want speak", tool["name"])
	}
	schema, ok := tool["inputSchema"].(map[string]any)
	if !ok {
		t.Fatalf("inputSchema = %v, want object", tool["inputSchema"])
	}
	if schema["type"] != "object" {
		t.Errorf("inputSchema.type = %v, want object", schema["type"])
	}
	props := schema["properties"].(map[string]any)
	for _, name := range []string{"text", "priority", "provider", "lang", "now"} {
		if _, ok := props[name]; !ok {
			t.Errorf("inputSchema without property %q: %v", name, props)
		}
	}
	if len(props) != 5 {
		t.Errorf("inputSchema has %d properties (%v), want exactly the 5 from the brief", len(props), props)
	}
	if req, ok := schema["required"].([]any); !ok || len(req) != 1 || req[0] != "text" {
		t.Errorf("required = %v, want [text]", schema["required"])
	}

	// 4. tools/call: admission like POST /speak — "queued: <id>" and the
	//    announcement shows up at the fake provider (same queue, no
	//    parallel path).
	raw = mcpPost(t, d, `{"jsonrpc":"2.0","id":4,"method":"tools/call","params":{"name":"speak","arguments":{"text":"hello via mcp"}}}`)
	if raw.status != http.StatusOK {
		t.Fatalf("tools/call: status %d — body: %s", raw.status, raw.body)
	}
	m = mcpDecode(t, raw)
	if fmt.Sprint(m["id"]) != "4" {
		t.Errorf("tools/call id = %v, want echo 4", m["id"])
	}
	text := mcpToolText(t, m)
	if !strings.HasPrefix(text, "queued: ") || len(text) <= len("queued: ") {
		t.Fatalf("tools/call text = %q, want \"queued: <id>\"", text)
	}
	if mcpIsError(m) {
		t.Errorf("tools/call isError = true on successful admission: %v", m)
	}
	hits := fake.waitCompleted(t, 1)
	if hits[0].Text != "hello via mcp" {
		t.Errorf("fake hit = %q, want the MCP announcement", hits[0].Text)
	}
}

// TestMCPToolsCallLaws: muted and law discards are tool RESULTS
// (isError:false with explanatory text), not protocol errors — and the
// announcement stays silent.
func TestMCPToolsCallLaws(t *testing.T) {
	t.Run("muted", func(t *testing.T) {
		root := t.TempDir()
		fake := newFakeProvider(t, 0)
		d := startDaemon(t, root, fake.srv.URL, nil)
		postPath(t, d, "/mute")

		m := mcpDecode(t, mcpPost(t, d, `{"jsonrpc":"2.0","id":7,"method":"tools/call","params":{"name":"speak","arguments":{"text":"silence please"}}}`))
		if mcpIsError(m) {
			t.Fatalf("muted is isError:true — should be a result: %v", m)
		}
		if text := mcpToolText(t, m); !strings.HasPrefix(text, "muted") {
			t.Errorf("text = %q, want the muted explanation", text)
		}
		fake.assertNoHits(t, 300*time.Millisecond)
	})

	t.Run("rate_limit discards low", func(t *testing.T) {
		root := t.TempDir()
		fake := newFakeProvider(t, 0)
		d := startDaemon(t, root, fake.srv.URL, map[string]string{"TALK_RATE_LIMIT": "30s"})

		// The first low announcement plays (window free) and books it.
		m := mcpDecode(t, mcpPost(t, d, `{"jsonrpc":"2.0","id":8,"method":"tools/call","params":{"name":"speak","arguments":{"text":"first","priority":"low"}}}`))
		if text := mcpToolText(t, m); !strings.HasPrefix(text, "queued: ") {
			t.Fatalf("first low: text = %q, want queued", text)
		}
		fake.waitCompleted(t, 1)

		// Second low inside the window: discard as a result.
		m = mcpDecode(t, mcpPost(t, d, `{"jsonrpc":"2.0","id":9,"method":"tools/call","params":{"name":"speak","arguments":{"text":"second","priority":"low"}}}`))
		if mcpIsError(m) {
			t.Fatalf("discard is isError:true — should be a result: %v", m)
		}
		if text := mcpToolText(t, m); !strings.HasPrefix(text, "discarded: rate_limit") {
			t.Errorf("text = %q, want discarded: rate_limit …", text)
		}
		fake.assertNoFurtherArrivals(t, 300*time.Millisecond)
	})

	t.Run("quiet_hours discards", func(t *testing.T) {
		root := t.TempDir()
		fake := newFakeProvider(t, 0)
		d := startDaemon(t, root, fake.srv.URL, map[string]string{
			"TALK_QUIET_HOURS": windowAround(),
		})

		m := mcpDecode(t, mcpPost(t, d, `{"jsonrpc":"2.0","id":10,"method":"tools/call","params":{"name":"speak","arguments":{"text":"at night"}}}`))
		if mcpIsError(m) {
			t.Fatalf("quiet-hours discard is isError:true — should be a result: %v", m)
		}
		if text := mcpToolText(t, m); !strings.HasPrefix(text, "discarded: quiet_hours") {
			t.Errorf("text = %q, want discarded: quiet_hours …", text)
		}
		fake.assertNoHits(t, 300*time.Millisecond)
	})
}

// TestMCPErrorPaths: validation errors as JSON-RPC errors (-32602), unknown
// method -32601, broken JSON -32700, wrong jsonrpc version and batches
// -32600, GET /mcp 405 (no server-initiated streams).
func TestMCPErrorPaths(t *testing.T) {
	root := t.TempDir()
	fake := newFakeProvider(t, 0)
	d := startDaemon(t, root, fake.srv.URL, nil)

	cases := []struct {
		name    string
		payload string
		code    float64
		msgPart string
	}{
		{"text missing", `{"jsonrpc":"2.0","id":21,"method":"tools/call","params":{"name":"speak","arguments":{}}}`, -32602, "text"},
		{"text empty", `{"jsonrpc":"2.0","id":22,"method":"tools/call","params":{"name":"speak","arguments":{"text":"   "}}}`, -32602, "text"},
		{"invalid priority", `{"jsonrpc":"2.0","id":23,"method":"tools/call","params":{"name":"speak","arguments":{"text":"x","priority":"mega"}}}`, -32602, "priority"},
		{"unknown tool", `{"jsonrpc":"2.0","id":24,"method":"tools/call","params":{"name":"sing","arguments":{"text":"x"}}}`, -32602, "sing"},
		{"unknown method", `{"jsonrpc":"2.0","id":25,"method":"resources/list"}`, -32601, "resources/list"},
		{"broken JSON", `{"jsonrpc":"2.0","id":`, -32700, "JSON"},
		{"wrong jsonrpc version", `{"jsonrpc":"1.0","id":26,"method":"ping"}`, -32600, "2.0"},
		{"batch (removed since 2025-06-18)", `[{"jsonrpc":"2.0","id":27,"method":"ping"}]`, -32600, "batch"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			raw := mcpPost(t, d, tc.payload)
			if raw.status != http.StatusOK {
				t.Fatalf("status = %d, want 200 (JSON-RPC error in the body)", raw.status)
			}
			m := mcpDecode(t, raw)
			rpcErr, ok := m["error"].(map[string]any)
			if !ok {
				t.Fatalf("no error object: %v", m)
			}
			if rpcErr["code"] != tc.code {
				t.Errorf("code = %v, want %v (body: %s)", rpcErr["code"], tc.code, raw.body)
			}
			if msg, _ := rpcErr["message"].(string); !strings.Contains(msg, tc.msgPart) {
				t.Errorf("message = %q, want part %q", msg, tc.msgPart)
			}
			if _, hasResult := m["result"]; hasResult {
				t.Errorf("error response with result: %v", m)
			}
		})
	}

	t.Run("ping", func(t *testing.T) {
		m := mcpDecode(t, mcpPost(t, d, `{"jsonrpc":"2.0","id":28,"method":"ping"}`))
		if _, ok := m["result"]; !ok {
			t.Fatalf("ping without result: %v", m)
		}
	})

	t.Run("GET /mcp → 405 (no server-initiated streams)", func(t *testing.T) {
		raw := doRequest(t, http.MethodGet, d.baseURL+"/mcp", nil, "")
		if raw.status != http.StatusMethodNotAllowed {
			t.Fatalf("GET /mcp status = %d, want 405", raw.status)
		}
		if allow := raw.header.Get("Allow"); !strings.Contains(allow, "POST") {
			t.Errorf("Allow = %q, want POST named", allow)
		}
	})

	t.Run("notification with unknown method → silent 202", func(t *testing.T) {
		raw := mcpPost(t, d, `{"jsonrpc":"2.0","method":"notifications/roots/list_changed"}`)
		if raw.status != http.StatusAccepted || raw.body != "" {
			t.Fatalf("status %d body %q, want 202 without body", raw.status, raw.body)
		}
	})
}

// TestStatusMCPField: /status reports mcp:true (compat field Task 06).
func TestStatusMCPField(t *testing.T) {
	root := t.TempDir()
	fake := newFakeProvider(t, 0)
	d := startDaemon(t, root, fake.srv.URL, nil)
	if st := getStatus(t, d); !st.MCP {
		t.Error("mcp = false, want true (endpoint is present)")
	}
}